Bump NUnit from 4.2.2 to 4.3.2 in /src

Bumps [NUnit](https://github.com/nunit/nunit) from 4.2.2 to 4.3.2.
- [Release notes](https://github.com/nunit/nunit/releases)
- [Changelog](https://github.com/nunit/nunit/blob/main/CHANGES.md)
- [Commits](nunit/nunit@4.2.2...4.3.2)

---
updated-dependencies:
- dependency-name: NUnit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/Directory.Packages.props

@@ -47,7 +47,7 @@
     <PackageVersion Include="NServiceBus.Transport.SqlServer" Version="8.1.6" />
     <PackageVersion Include="NServiceBus.Transport.PostgreSql" Version="8.1.6" />
     <PackageVersion Include="NuGet.Versioning" Version="6.12.1" />
-    <PackageVersion Include="NUnit" Version="4.2.2" />
+    <PackageVersion Include="NUnit" Version="4.3.2" />
     <PackageVersion Include="NUnit.Analyzers" Version="4.5.0" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
     <PackageVersion Include="Particular.Approvals" Version="2.0.0" />